1. Field of Use
This invention relates generally to apparatus for waterless hulling of small-diameter fruit and vegetable products such as nuts, corn kernels, grains and the like.
In particular, it relates to improved means for introducing and removing products from the apparatus and, furthermore, to improved means for controlling hull removal while in the apparatus.
2. Description of the Prior Art
Prior art apparatus for cleaning and peeling fruit and vegetable products, such as potatoes, carrots, and the like, typically employs rotatable roller brushes in various arrangements to abrade the outer layer of skin from the product. The following U.S. Pat. Nos. illustrate the state of the art: 4,258,069; 4,230,034; 3,811,000 and 2,355,810.
In some prior art arrangements a plurality of rotatable roller brushes are arranged in radially spaced-apart relationship about a horizontal main axis to define a rotatable roller cage having a product-receiving chamber therewithin. Typically, a rotatable auger or other means within the chamber is employed to do two things: first, advance the product axially therethrough and, two, force the product to engage the roller brushes so that the brushes can clean and peel the product. Furthermore, water is injected or sprayed into the chamber and onto the product to enable or facilitate the cleaning and peeling process.
However, the use of such augers or similar devices to force the product against the brushes substantially reduces the volumetric capacity of the chamber and limits the amount of product that can be processed at a given time. Furthermore, such forcing can inflict physical damage on the product being processed thereby causing waste and adding to the cost and complexity of the apparatus. The use of water during processing can adversely affect the texture and moisture content of the finished product, can cause a sludge-like mixture of peelings and dirt to accumulate within the chamber and on the product which adversely affects the quality of the finished product and which can, in some cases, actually interfere with and inhibit the cleaning/peeling process.
My U.S. Pat. No. 5,106,641 issued Apr. 21, 1992 entitled APPARATUS AND METHOD FOR WATERLESS ROTARY CLEANING AND PEELING FOOD PRODUCTS AND THE LIKE provides improved apparatus and method for using rotatable abrading rollers to clean and peel products, such as fruits, vegetables, nuts, kernels and the like, without the need for augers or the like to move and direct the product against the roller brushes and without the use of water during processing.
The improved apparatus in my U.S. Pat. No. 5,106,641 broadly comprises a plurality of rotatable roller brushes arranged to define a rotatable roller cage having a product-receiving chamber therewithin with a main axis which is sloped slightly downwardly from horizontal. Means are provided to rotate the roller cage in one direction and to rotate each roller brush in the opposite direction. Each roller brush comprises bristles around its circumference. Means are provided to feed the product into the high inlet end of the chamber and to impart rotational movement to the product as it is being fed into the chamber.
In accordance with my U.S. Pat. No. 5,106,641, the rotational speed of the roller cage, the rate at which product is fed into the chamber and the initial rotational speed of the product entering the chamber are regulated, taking into account the size, shape and weight of the product, so that substantially only one layer of product is disposed against the majority of roller brushes defining the wall of the chamber. As each piece of product nears the top of the chamber, assuming counter-clockwise cage rotation, gravity causes the piece to disengage the rollers near the 1 o'clock position, travel across the top of the chamber, and reengage the rollers near the 11 o'clock position.
Each roller has abrasive means, such as bristles or abrasive material, around its entire circumference. At any given moment, half of the abrasive means confront the chamber. During roller rotation, the abrasive means confronting the chamber move arcuately through a first (incoming) quadrant toward the chamber and then through a second (outgoing) quadrant away from the chamber. Therefore, an unhulled nut deposited between adjacent rollers by centrifugal force is subjected to two opposing forces. More specifically, as the abrasive means in the outgoing quadrant of one roller tends to draw the nut into the space between the rollers, the abrasive means in the incoming quadrant of the other roller tends to push the nut out of the space between the rollers. Furthermore, some of the hull scraped therefrom is flung outwardly of the chamber (which is desirable) and some is flung inwardly (which is undesirable).
In operation, the pieces of product entering the chamber are flung against the chamber wall and are held thereagainst in a single layer by centrifugal force as the cage rotates, except in the region near the top of the chamber, as explained above. At the same time, the bristles of the rotating roller brushes clean and peel the product. As explained above, the bristles cause most peelings to be flung outwardly of the chamber, but some are flung inwardly. The slope of the chamber causes the product to advance toward and exit through the outlet opening at the low end of the chamber. The amount of centrifugal force employed to keep a layer of product against the roller brushes is kept at a minimum so, assuming that the cage rotates counterclockwise and that the highest point of cage rotation is at "12 o'clock", a piece of product can be raised to near the 1 o'clock position whereat it becomes airborne until it reaches the 11 o'clock position. The product pieces tumble and rotate as they are engaged by the bristles and this ensures that all of the outer surface of each piece of product is cleaned and peeled by the time it passes through the chamber.
The apparatus in my U.S. Pat. No. 5,106,641 is very well-suited for its intended purposes, but it is desirable to improve its efficiency.